The present invention relates generally to a process for the compression of redundant sequences of serial data elements and more particularly a process for the compression of redundant sequences of serial data elements, which are divided into partial sequences or sequence components each having any number of data elements and a closing character, and also a process for decompression of such compressed sequences of serial data elements.
Communications and specifically data sequences are frequently redundant to a high degree, that is to say, they contain a substantially larger number of data elements or characters than would be required for representing the information contained in the communication message. An example in this respect is the transmission of television pictures wherein the fields which are successively recorded and then stored or transmitted are identical, in regard to those areas of a scene which have not experienced any change in regard to the position, brightness or colour of the picture points or elements. This is generally the situation with the major part of all picture points or elements. Therefore, in a known process for reducing the degree of redundancy in television pictures, the transmission of signals is restricted to those picture points or groups of picture points, in which there has been a change between the fields.
There are of course other examples of redundancy situations similar to that described above with reference to television transmission, such as for example language texts which tend to be redundant to a high degree, for they use inter alia units of a dictionary which are very often made up of identical sequence components of smaller units (for example letters).